1. Field of the Invention
This invention relates to measuring devices utilizing a variable color digital display.
2. Description of the Prior Art
A display device that can change color and selectively display characters is described in my U.S. Pat. No. 4,086,514, issued on Apr. 25, 1978 and entitled Variable Color Display Device.
Multimeters with monochromatic digital display are well known and extensively used. Such multimeters, however, are capable of indicating value of only one measured quantity at a time. They are not capable of simultaneously indicating values of two different quantities, nor are they capable of indicating the relationship of instantly displayed measured value to values measured at other times, nor are they capable of indicating the relationship of the displayed measured value to measurement limits.
A hand held testing device for measuring different electrical quantities disclosed in U.S. Pat. No. 4,298,837, issued on Nov. 3, 1981 to Manfred Koslar, includes test prongs, function and range selectors, and display mounted within a handle such that they may be viewed together.
A digital ohmmeter with electrical continuity tester disclosed in U.S. Pat. No. 4,228,394, issued on Oct. 14, 1980 to John B. Crosby, includes a digital readout, for displaying the measured value of resistance, on which an Omega symbol may be energized to give a rapid indication of the continuity condition.